This seems to be a typical defect in the touchpad of a lot of Dell laptops. My experience has been that the only was to fully fix this problem is to purchase a new keyboard, palmrest and touchpad for the machine. You can check the Dell site too and see if there are driver updates for the device but most of the time this will not fix the problem.

Hi, I have just reported this problem too. I managed to stop the pointer from doing this by attaching an external mouse. It was a usb mouse that had a round mouse connector attachment on the usb. This meant that I didn't have to waste the usb port. It stopped the problem... but maybe it's temporary. I disconnected the external mouse and the pointer was behaving normally again. I don't know if it'll happen again, but it's worth a try if you're desperate. Good luck.

I got the same problem with the mouse pointer of my Dell D600. I resolved it last day successfully by myself. At first I opened the casing and shielded the metal bracket covering touchpad. This did not work. I then disabled the mouse stick on the keyboard from the control panel and the touchpad started working drastically fine and the pointer is working with proper control.